@set, @clear, and @value

You can direct the Texinfo formatting commands to format or ignore parts of a Texinfo file with the @set, @clear, @ifset, and @ifclear commands.

Brief descriptions:

@set flag [value]

Set the variable flag, to the optional value if specifed.

@clear flag

Undefine the variable flag, whether or not it was previously defined.

@ifset flag

If flag is set, text through the next @end ifset command is formatted. If flag is clear, text through the following @end ifset command is ignored.

@ifclear flag

If flag is set, text through the next @end ifclear command is ignored. If flag is clear, text through the following @end ifclear command is formatted.

• set value: Expand a flag variable to a string.
• ifset ifclear: Format a region if a flag is set.
• value Example: An easy way to update edition information.